The reason why they haven't had celebrities play in 13 years is because they were the most part terrible. When was the last time celebrities or professional athletes played by themselves? The game just dragged. Pairing them up with contestants didn't help, they just really served to spin the wheel but were otherwise clueless.
Honestly, I've been regularly watching the show for the past few years, and the celebs probably aren't going to be any worse than the college weeks they've perennially done. I don't know where they scout their contestants from for those, but it's painful watching when it seems like 80% of the contestants look live they've done next to no preparation or even know the game.
This same problem is also happening this season with the show focusing almost solely on southern California contestants due to the pandemic. The gameplay has dipped terribly and they seem so desperate for contestants that some people seem like they walked in off the street and just started playing. Some to great heights, but most to "WTF?" response.
So, I'll gladly be looking forward to what will be part of the shot in the arm Wheel needed. The two biggest gripes I had as Harry walked out the door was the massive lack in fun/creative/current puzzle writing and no celebs. They might not be good, but they're entertaining and people like watching the favorite stars play the games they like to watch. Here's hoping being in primetime they book some big names.